Arginine-vasopressin and endothelium-associated proteins in thyroid disease

Plasma concentrations of endothelium-derived proteins (fibronectin and von Willebrand factor), liver synthesized proteins (haptoglobin, transferrin, ceruloplasmin, alpha 1-antitrypsin, antithrombin III and factor VIII-coagulant) and plasma arginine-vasopressin (AVP) were measured in 12 hyperthyroid, 9 hypothyroid and 15 age- and sex-matched normal controls. In hyperthyroid patients the plasma concentrations of AVP and endothelium-associated proteins (EAP) were significantly higher than in the control group (p less than 0.05 and p less than 0.01 respectively). Rendering hyperthyroid patients into the euthyroid state significantly lowered AVP (p less than 0.01), fibronectin (p less than 0.05) and von Willebrand factor (p less than 0.01) compared with pretreatment levels. Hypothyroid patients were studied at diagnosis and after replacement therapy with levothyroxine. Compared with pretreatment values, significant increases were noted in plasma concentrations of von Willebrand factor, fibronectin and AVP (p less than 0.01). With the exception of factor VIII-coagulant, the concentrations of hepatic synthesized proteins did not deviate from normal values in hyperthyroid and hypothyroid patients. Significant correlations were found between serum-free thyroxine on the one hand and the plasma concentrations of fibronectin (p less than 0.005), von Willebrand factor (p less than 0.001) and AVP (p less than 0.0001). Similarly, there was significant correlation between the plasma concentrations of AVP on the one hand and fibronectin (p less than 0.002) and von Willebrand factor (p less than 0.01). The results demonstrate elevated plasma levels of AVP in hyperthyroid patients and an increase during levothyroxine treatment of hypothyroid patients.(ABSTRACT TRUNCATED AT 250 WORDS)